Consider the hyperbola xy = 4 and a line 2x + y = 4. O is the centre of the hyperbola. Tangent at any point P on the hyperbola intersects the coordinate axes at A and B.
Locus of circumcentre of ΔOAB is
A parabola
Locus of circum centre is rectangular hyperbola.
R = (2, 0) Any point through R is (2+r cos θ, r sin θ)
⇒(2+r cos θ)(r sin θ)=4⇒r2sin θ cos θ+2r sin θ=4∴r1r2=∣∣4sin θ cos θ∣∣≥8